User Task Delegation in ApplicationsFriedger MüffkeOpenIntents.org

Campus Party 2012 Berlin

Getting a 3-Months Job Done in 30 MinutesFriedger MüffkeOpenIntents.org

Campus Party 2012 Berlin

Context

Task-driven software engineering

User taskInteraction design

Application platform with monolithic applications that perform user tasks

History of Sharing between Application

Interprocess communication (IPC)

● Objects ○ Windows: DDE/COM○ J2EE: JavaBeans

● Functionality○ WebServices + UDDI○ RPC

● Graphical User Interface○ Dynvoker, TU Dresden (WS/GUI annotations)

Problem Description

User Task Delegation is an architecture pattern designed to address the problem of a Component (Site/App) wanting to do a certain User Task (Action) with a Partner known to the User but not the Component.

NASCAR problem

Examples● Share

Twitter, Email,..

● PickPicasa, Flickr, Youtube, Webcam,..

● Editimage, document, ..

● SaveGoogle Drive, locally, ..

● PropsLike, praise, +1, ..

● PrintFax, pdf, ..

● LogInOpenId

● SubscribeNotifications by e-mail, sms, ..

● SearchWikipedia, dictionary, ..

● Check-in and other Activity Stream verbs

Android: Intents

● Freely definable actions● Central repository in platform● Registration on install time● PackageManagerService class● No official discovery, but openintents.

org/en/registry

Android: Intents

in Manifest.xml

<intent-filter> <action android:name= "android.intent.VIEW"/> <data android:scheme = "http"/></intent-filter>

in Application

Intent intent = new Intent();intent.setAction(Intent.ACTION_VIEW);intent.setData("http://campus-party.eu");context.startActivity(intent);

Web Apps: WebIntents/WebActivities

● Specified as W3C draft and Mozilla proposal● User agent manages registry● Registration on visit or programmatically● Suggestions via Chrome Web Store● discovery maybe via openintents.

org/en/registry

Web Apps: WebIntents/WebActivities

Available in Chrome Canary Build

Web Apps: WebIntents/WebActivities

var startActivity = window.navigator.startActivity || window.navigator.webkitStartActivity;

var imageUrl = document.getElementById("main-image").src;

var intent = new Intent("http://webintents.org/share",

"image/*", imageUrl);

var onSuccess = function(data) { /* woot */ };var onError = function(data) { /* boooo */ };

startActivity.call(intent, onSuccess, onError);

WP7 / Win 8: Contracts/Extensions

● Defined by platform● More specific tasks (e.g. account picture)● Agreement between two apps or between

app and Windows● Different API (code) for each user task● Declarative registration for serving apps● Event handlers● No discovery

WP7 / Win 8: Contracts/Extensionsin client app (sharing)var dataTransferManager = Windows.ApplicationModel.DataTransfer. DataTransferManager.getForCurrentView();dataTransferManager.addEventListener("datarequested", function (e) { // Code to handle event goes here. });

in serving app (file picker)<Extension Category="windows.fileOpenPicker" StartPage="fileOpenPicker.html"> <FileOpenPicker> <SupportedFileTypes> <SupportsAnyFileType /> </SupportedFileTypes> </FileOpenPicker>

Definition

User Task Delegation is an architecture pattern where semantically defined tasks are performed by third-party components.

1. Task definition 2. Registration of serving components3. Invocation by client component4. Selection from registry by platform with help of user5. Delivery to service6. Response from serving component to client component

Further topics

● Discovery for developers and users● Dependency Management

● Implicit vs. explicit delegation● Delegation architecture vs.

trusted subsystem● Data flow and security/privacy● Remote Delegation (e.g. PLAY_TO)● Between Native and Web

Android Meets WebIntents

● Google Summer of Code 2012 project● Cheng Zheng, mentored by OpenIntents● Deliverables:

○ User agent with registry and native app integration○ Helper lib for extended chooser dialog○ Sample app

https://github.com/openintents/gsoc2012/wiki

Android Meets Web

Questions ?

Friedger Müffkeopenintents.org

@fmdroidgplus.to/friedger

Links

Android Intents

WebIntents SpecificationWebActivities

Windows 8 Contracts and Extensions